RFID tag and method of manufacturing the same

ABSTRACT

A radio frequency identification (RFID) tag and method of manufacturing the same. In a preferred embodiment, the RFID tag includes a radio frequency (RF) inlay, the RF inlay including a carrier sheet, an antenna printed on the carrier sheet and a wireless communication device bonded to the antenna. The RFID tag also includes a plastic extrudate, the RF inlay being disposed within the extrudate so that the antenna and the wireless communication device are encapsulated on all sides within the extrudate. Optional metallic reflector and mounting adhesive layers may be laminated onto the underside of the extrudate. The present invention is also directed to an automated method for manufacturing the above RFID tag, such a method involving, in one embodiment, feeding a continuous supply of RF inlays into a cross-head extruder to yield a continuously extruded block and then cutting the block between successive antennae to yield a plurality of individual RFID tags.

CROSS-REFERENCE TO RELATED APPLICATIONS

The present application is a continuation of U.S. patent applicationSer. No. 10/777,456, inventors Cullen et al., filed Feb. 12, 2004, thedisclosure of which is incorporated herein by reference.

BACKGROUND OF THE INVENTION

The present invention relates generally to wireless communicationdevices and more particularly to a novel radio frequency identification(RFID) tag and to a method of manufacturing said RFID tag.

Current inventory and manufacturing methods rely on the ability to trackand identify items, such as packages, containers, individual parts,inventory items or other similar items of concern, and to communicateinformation relating to said items in a wireless manner. One method oftracking and providing information relating to an item is to incorporatea wireless communication device, such as an active or passivetransponder, into an identification tag that responds to wirelessinterrogation and commands and, in turn, to attach said identificationtag directly to the item. The tag is preferably designed to store orrepresent pertinent information relating to the item to which it isattached, such as a unique identifying number, an expiration date, a“born on” date, manufacturing information, shipment status and the like.

A radio frequency identification (RFID) tag is one well-known type ofwireless communication device which transmits and/or receivesinformation relating to an item using radio frequency (RF) signals.

One well-known type of RFID tag includes an antenna and an integratedcircuit (IC) chip mounted on the antenna. The aforementioned componentsare typically enclosed within a two-piece plastic housing or package. Inoperation, the IC chip is programmed to store pertinent informationrelating to the item to which the RFID tag is secured. In response to anappropriate interrogation signal, the IC chip converts said programmedinformation into a corresponding electromagnetic signal which ispropagated as radio frequency (RF) waves by the antenna.

Although RFID tags of the type described above are suitable for use onmany different types of items, such tags are not well-suited for use onmetallic items for the reason that metallic items tend to interfere withthe RF signal transmitted by the RFID tag antenna.

Accordingly, one approach to remedy this problem has been to provide theRFID tag with a metallic reflector which makes the RFID tag moretolerant of nearby metals while retaining its RF functionality.Specifically, a metallic reflector is secured to the outer surface ofthe plastic package housing the antenna and IC chip. In use, themetallic reflector functions as an electrically conductive back planewhich reflects RF signals transmitted by the RFID tag antenna away fromthe metal item to which the RFID tag is secured. In this respect, themetallic reflector serves to effectively insulate the RFID tag from themetal object to which it is secured, which is highly desirable.

An example of an RFID tag of the aforementioned type is disclosed inU.S. Pat. No. 6,501,435, inventors King et al., which issued Dec. 31,2002, and which is incorporated herein by reference.

RFID tags having a metallic reflector are commonly manufactured in thefollowing manner. First, using injection molding, a plastic base and aplastic cover for the RFID tag package are separately formed, the baseand/or the cover being appropriately contoured to matingly receive theRFID tag package. After said injection molding step, the RFID tagantenna, which is commonly constructed as a thin strip of etched copperfoil, is secured to the top surface of the plastic base. It should benoted that, rather than securing the antenna to the base in a separatestep, the plastic base may, in the alternative, be injection moldedaround the antenna. Either immediately prior to or immediate after theantenna is secured to the base, the IC chip for the RFID tag is solderedto the top surface of the antenna. With the antenna and IC chip coupledto the base, the plastic cover is then sonic-welded, by hand, to the topof the plastic base so as to enclose the antenna and IC chiptherebetween. In a final step, the metallic reflector is secured to thebottom surface of the base using an adhesive.

RFID tags manufactured in the method described above suffer from acouple of notable shortcomings.

One such shortcoming of the foregoing approach is that the molds used tomake the injection molded base and cover are typically only sized foruse with an antenna (and IC chip) of a particular size. Consequently, ifone wishes to vary the dimensions of the antenna (e.g., to tune theantenna for different applications), one must obtain new molds formanufacturing the base and cover. This is highly undesirable as moldsare quite expensive.

Another shortcoming of the foregoing approach is the low throughput ofthe process for manufacturing and assembling the tag. As noted above,each tag is manufactured, one at a time, using a labor-intensive andtime-consuming process.

SUMMARY OF THE INVENTION

It is an object of the present invention to provide a new radiofrequency identification (RFID) tag and method of manufacturing thesame.

It is another object of the present invention to provide an RFID tag andmethod of manufacturing the same that overcome at least some of theshortcomings associated with existing RFID tags and their methods ofbeing manufactured.

It is yet another object of the present invention to provide an RFID tagand method of manufacturing the same that is well-suited formass-production at a high rate of throughput.

According to one aspect of the present invention, there is provided atag comprising (a) an inlay, said inlay comprising (i) an antenna, and(ii) a wireless communication device coupled to said antenna; and (b) aplastic extrudate, said plastic extrudate encapsulating said antenna andsaid wireless communication device.

According to another aspect of the present invention, there is provideda tag comprising (a) a plastic casing comprising (i) a bottom membershaped to define a longitudinal cavity and (ii) a top member applied tosaid bottom member to at least partially enclose the longitudinalcavity, and (b) an inlay disposed within the longitudinal cavity, saidinlay comprising, (i) a carrier sheet, (ii) an antenna disposed on saidcarrier sheet, and (iii) a wireless communication device coupled to saidantenna.

According to yet another aspect of the present invention, there isprovided a method of continuously manufacturing a plurality of tags,each tag comprising a plastic extrudate and an inlay surrounded by saidplastic extrudate, said method comprising the steps of (a) providing acontinuous supply of inlays, said continuous supply of inlays comprisinga continuous carrier web, a plurality of antennae positioned on saidcontinuous carrier web at spaced intervals and a wireless communicationdevice coupled to each of said antennae, (b) feeding said continuoussupply of inlays into a cross-head extruder so as to yield a continuousblock which includes said continuous supply of inlays surrounded by aplastic extrudate, and (c) cutting said continuous block betweensuccessive antennae so as to yield individual tags.

According to still another aspect of the present invention, there isprovided a method of continuously manufacturing a plurality of tags,said method comprising the steps of (a) providing a single continuousstrip which is shaped to include a continuous longitudinal cavity alongits entire length, (b) depositing a continuous supply of inlays into thecontinuous longitudinal cavity, said continuous supply of inlayscomprising a carrier web, a plurality of antennae disposed on saidcarrier web at spaced intervals, and a wireless communication devicecoupled to each of said antennae, (c) applying a cover over saidcontinuous supply of inlays disposed within said single continuousstrip, and (d) cutting said cover, said continuous supply of inlays andsaid single continuous strip between successive antennae to yieldindividual tags.

According to still yet another aspect of the present invention, there isprovided a method of continuously manufacturing a plurality of tags,each tag comprising a plastic casing and an inlay encased within saidplastic casing, said method comprising the steps of (a) providing asingle continuous strip having a plurality of cavities at spacedintervals, (b) depositing an inlay within each cavity in said singlecontinuous strip, each inlay comprising a carrier sheet, an antennadisposed on said carrier sheet and a wireless communication devicecoupled to said antenna, (c) applying a single continuous web to saidsingle continuous sheet to enclose each inlay within its correspondingcavity, and (d) cutting said single continuous strip and said singlecontinuous web between successive cavities to yield individual tags.

According to a further aspect of the present invention, there isprovided a method of continuously manufacturing a plurality of tags,each tag comprising a plastic casing and an inlay encased within saidplastic casing, said method comprising the steps of (a) providing asingle continuous member having a plurality of cavities at spacedintervals, (b) depositing an inlay within each cavity in said singlecontinuous strip, each inlay comprising a carrier sheet, an antennadisposed on said carrier sheet and a wireless communication devicecoupled to said antenna, (c) applying a plug over each inlay to enclosesaid inlay within its corresponding cavity, and (d) cutting said singlecontinuous strip between successive cavities.

The present invention is also directed to a continuous supply of inlays,said continuous supply of inlays comprising (a) a continuous web, (b) aplurality of antennae disposed on the top surface of said continuous webat spaced intervals, and (c) a plurality of wireless communicationdevices, each wireless communication device being coupled to acorresponding antenna.

Various other features and advantages will appear from the descriptionto follow. In the description, reference is made to the accompanyingdrawings which form a part thereof, and in which is shown by way ofillustration, various embodiments for practicing the invention. Theembodiments will be described in sufficient detail to enable thoseskilled in the art to practice the invention, and it is to be understoodthat other embodiments may be utilized and that structural changes maybe made without departing from the scope of the invention. The followingdetailed description is therefore, not to be taken in a limiting sense,and the scope of the present invention is best defined by the appendedclaims.

BRIEF DESCRIPTION OF THE DRAWINGS

In the drawings wherein like reference numerals represent like parts:

FIG. 1 is a perspective view of a first embodiment of a radio frequencyidentification (RFID) tag constructed according to the teachings of thepresent invention, said tag being broken away in part to more clearlyshow the carrier sheet and antenna of the RF inlay;

FIG. 2 is a longitudinal section view of the RFID tag shown in FIG. 1;

FIG. 3 is an enlarged, fragmentary, top plan view of the RF inlayantenna shown in FIG. 2, the RF inlay being shown with the wirelesscommunication device removed therefrom;

FIG. 4 is a fragmentary, simplified, schematic view of an automatedmethod for continuously manufacturing a supply of the RFID tags shown inFIG. 1;

FIG. 5 is a perspective view of a second embodiment of an RFID tagconstructed according to the teachings of the present invention;

FIG. 6 is a longitudinal section view of the RFID tag shown in FIG. 5;

FIG. 7 is a simplified schematic view of an automated method forcontinuously manufacturing a supply of the RFID tags shown in FIG. 5;

FIG. 8 is a perspective view of a third embodiment of an RFID tagconstructed according to the teachings of the present invention, saidtag being broken away in part to more clearly show the carrier sheet andantenna of the RF inlay;

FIG. 9 is a longitudinal section view of the RFID tag shown in FIG. 8;

FIG. 10 is a perspective view of a fourth embodiment of an RFID tagconstructed according to the teachings of the present invention, saidtag being broken away in part to more clearly show the carrier sheet andantenna of the RF inlay;

FIG. 11 is a simplified schematic view, shown partly in section, of anautomated method for continuously manufacturing a supply of the RFIDtags shown in FIG. 10;

FIG. 12 is a perspective view of a fifth embodiment of an RFID tagconstructed according to the teachings of the present invention, thebottom member of said tag being broken away in part to more clearly showthe carrier sheet and antenna of the RF inlay;

FIG. 13 is a longitudinal section view of the RFID tag shown in FIG. 12;and

FIG. 14 is a longitudinal section view of a sixth embodiment of an RFIDtag constructed according to the teachings of the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

Referring now to FIGS. 1 and 2, there are shown perspective and sectionviews, respectively, of a first embodiment of a radio frequencyidentification (RFID) tag constructed according to the teachings of thepresent invention and identified generally by reference numeral 11. Inoperation, RFID tag 11 is designed to be affixed onto a particular item(or packaging therefor) and, in response to an active or passive radiofrequency signal, wirelessly transmit information relating to said item.

RFID tag 11 comprises a radio frequency (RF) inlay 13 and a plasticextrudate 15, extrudate 15 surrounding or enveloping inlay 13 in themanner to be described below.

RF inlay 13 includes a carrier sheet 17, an antenna 19 formed on carriersheet 17 and a wireless communication device 21 mounted on antenna 19.

Carrier sheet 17 preferably comprises a heat-stable polymeric filmhaving a thickness in the range of about 2 mm to 5 mm. Examples ofmaterials suitable for use as carrier sheet 17 include, but are notlimited to, polyester films, polyethylene terephthalate (PET) films andpolyimide films (such as Kapton® polyimide film, which is commerciallyavailable from E.I. DuPont de Nemours and Company Corporation,Wilmington, Del.). Carrier sheet 17 is preferably manufactured as acontinuous web which can be wound into roll form, as will be describedfurther below.

Antenna 19 preferably comprises a conductive material (e.g., copper orsilver) of appropriate size and shape, which is printed directly ontothe top surface of carrier sheet 17. Preferably, antenna 19 is formed bydepositing a layer of the conductive material onto carrier sheet 17,laying a template over the layer of conductive material and then etchingaway portions of the conductive material (e.g., using an acid bath) inorder to leave remaining the desired shape of antenna 19. Alternatively,antenna 19 may be formed by printing a conductive ink in a desiredpattern directly onto carrier sheet 17.

Referring now to FIG. 3, there is shown an enlarged, fragmentary, topplan view of antenna 19 printed on carrier sheet 17. Antenna 19 ispreferably in the form of a bilaterally symmetrical dipole antenna whichincludes first and second conductive tabs 23 and 25, respectively, whichare substantially identical in shape. First conductive tab 23 includes afirst end 27 and a second end 29. Similarly, second conductive tab 25includes a first end 31 and a second end 33. Tabs 23 and 25 are linearlyarranged in an end-to-end relationship with first end 27 of first tab 23and second end 33 of second tab 25 spaced slightly apart from oneanother. A small, square-shaped conductive pad 35 is disposed inproximity to, but spaced apart from, first end 27 of first tab 23 andsecond end 33 of second tab 25. Together, first end 27 of first tab 23,second end 33 of second tab 25 and pad 35 define a landing area 37 onwhich wireless communication device 21 is conductively bonded. Antenna19 further comprises a pair of arcuate inductors 39 and 41 which connectfirst tab 23 to second tab 25, inductors 39 and 41 being disposed onopposite sides of landing area 35. In operation, inductors 39 and 41create a level of inductance across the wireless communication device 21bonded to landing area 35, thereby enabling the wireless communicationdevice 21 to operate at its peak performance.

Additional information pertaining to antenna 19 may be found in one ormore of the following commonly-assigned U.S. patent applications, all ofwhich are incorporated herein by reference: U.S. patent application Ser.No. 10/410,252, inventor Forster, filed Apr. 10, 2003; U.S. ProvisionalPatent Application Ser. No. 60/517,148, inventors Power et al., filedNov. 4, 2003; and U.S. Provisional Patent Application Ser. No.60/517,156, inventors Power et al., filed Nov. 4, 2003.

It should be understood that, although, in the present embodiment,antenna 19 is preferably a straight, center-fed, one-half wavelength,symmetric, dipole antenna, antenna 19 could be replaced with other typesof antennae, such as conventional antennae (e.g., a monopole antenna),without departing from the spirit of the present invention.

Wireless communication device 21 is preferably in the form of anintegrated circuit (IC) chip which is mounted on antenna 19. Wirelesscommunication device 21 is conductively bonded to landing surface 37 ofantenna 19 by any conventional means, such as through a solderingprocess or through the use of a conductive adhesive. In this manner, aconductive path is established between wireless communication device 21and antenna 19.

Wireless communication device 21 represents any conventional devicewhich, in response to an active or passive radio frequency signal,wirelessly transmits information relating to the particular item towhich RFID tag 11 is affixed. Preferably, wireless communication device21 is capable of transmitting signals at multiple resonant frequencies.

As noted above, carrier sheet 17 is preferably manufactured as anelongated web, which enables a plurality of RF inlays 13 to beconstructed using a common sheet 17. Specifically, a plurality ofantennae 19 are preferably printed on carrier sheet 17 at spacedintervals (e.g., between ¼ inch and ½ inch apart), each antenna 19having a corresponding wireless communication device 21 mounted thereon.In this manner, a plurality of interconnected RF inlays 13 may becreated which may then, in turn, be wound into an RF inlay supply roll.

Referring now to FIG. 4, there is shown a simplified schematicrepresentation of an automated method for continuously manufacturing asupply of RFID tags 11. In the manufacturing process, a plurality ofinterconnected inlays 13 in the form of an RF inlay supply roll 43 areintroduced from a reel 44 into a cross-head extruder 45. Specifically,cross-head extruder 45 is equipped with a die head 47, die head 47 beingprovided with a slot (not shown). RF inlay supply roll 43 is feddirectly into die head 47 through the aforementioned slot. As extruder45 generates heat, resin previously deposited into extruder 45 in pelletform begins to melt. The molten plastic in turn coaxially surrounds orenvelopes the portion of supply roll 43 which has been introduced intodie head 47. Extruder 45 then forces the molten thermoplastic materialout through die head 47 in a linear fashion to yield a continuouslyextruded block 49, block 49 comprising plastic extrudate 15 and supplyroll 43, with antenna 19 and wireless communication device 21 of each RFinlay 13 being encapsulated on all sides within extrudate 15. Continuousblock 49 is preferably transported away from cross-head extruder 45 bymeans of a linear conveyor belt (not shown).

It should be noted that plastic extrudate 15 preferably comprises adurable, thermoplastic material including, but not limited to, a rigidpolyvinyl chloride (PVC), a polyester, a polycarbonate, a polyethyleneor a polypropylene, which can be molded into a rectangular block shape.

After the extrusion process, a metallic reflector 51 is laminated ontothe bottom surface of block 49, preferably using a heat-activatableadhesive. The purpose of metallic reflector 51 is to reflect RF signalsgenerated by RF inlay 13 away from a metallic item to which RFID tag 11is secured, thereby effectively insulating RF inlay 13 from the metallicitem. Examples of suitable metals for use as metallic reflector 51include aluminum and/or copper. Preferably, metallic reflector 51 ismanufactured as a continuous sheet or strip of metal, said continuousstrip being wound onto a supply reel 53. In this manner, metallicreflector 51 can be continuously unwound from supply reel 53 andlaminated to the underside of block of thermoplastic material 49 toallow for the continuous assembly of RFID tags 11.

It should be noted that the application of metallic reflector 51 to theunderside of block 49 is optional and is only preferred when the item towhich RFID tag 11 is to be secured is metallic in nature. As a result,metallic reflector 51 could be eliminated entirely from the assemblyprocess.

It should be noted that, by modifying extruder die head 47 to include asecond slot, metallic reflector 51 may also be fed into die head 47 andsimultaneously surrounded within plastic extrudate 15 with inlay 13during the extrusion process.

After lamination of metallic reflector 51 onto block 49, the resultinglaminate is preferably advanced to a cooling station (not shown). At thecooling station, the laminate is passed through a water bath (not shown)approximately 15-20 feet long in order to fix, or set, the shape ofplastic extrudate 15.

A mounting adhesive 55 may be laminated onto the bottom surface ofmetallic reflector 51 so that tag 11 may be adhesively mounted onto adesired article. Preferably, adhesive 55 is manufactured as a continuoussheet or strip, said continuous strip being wound onto a supply reel 57.In this manner, adhesive 55 can be continuously unwound from reel 57 andsecured to the underside of metallic reflector 51.

It should be noted that, where it is not necessary or desirable toadhesively mount tag 11 onto an article, adhesive 55 is not needed andthe application of mounting adhesive 55 onto the underside of metallicreflector 51 may be eliminated from the assembly process.

In the final step of the assembly process, continuous block 49 (alongwith any reflectors 51 and adhesives 55 affixed thereto) is cut, asrequired, to form the individual RFID tags 11. It should be noted thatsensors (not shown) may be positioned along the linear conveyor belt tolocate antennae 19 within block 49 so that block 49 may be cut betweenadjacent antennae 19, as opposed to being cut within an antenna 19.Individual RFID tags 11 severed from block 49 can be packaged and/orshipped, as deemed necessary. The cut edges could be sealed usingtechniques, such as heat-crimping, application of a sealant orapplication of a suitable solvent.

It should be noted that, in an optional step prior to said cutting step,continuous block 49 (along with any reflectors 51 and adhesives 55affixed thereto) may be crimped between adjacent antennae 19.

Without wishing to limit the invention in any conceivable way to anyparticular embodiment of the invention, the present inventors herebydisclose the following preferred dimensions of RFID tag 11: RFID tag 11preferably has a height H (excluding adhesive 55) of approximately 5 mm,a length L of approximately 150 mm, and a width W of approximately 22mm.

It should be noted that numerous variations could be made to RFID tag 11(and its corresponding assembly process) without departing from thespirit of the present invention.

As an example, referring now to FIGS. 5 and 6, there are shownperspective and section views, respectively, of a second embodiment of aradio frequency identification (RFID) tag constructed according to theteachings of the present invention and identified generally by referencenumeral 111.

RFID tag 111 is similar to RFID tag 11 in that RFID tag 111 includes aradio frequency (RF) inlay 113 which is identical to RF inlay 13.Specifically, RF inlay 113 comprises an elongated carrier sheet 117preferably manufactured as a continuous web of heat-stable polymericfilm, an antenna 119 printed directly onto the top surface of carriersheet 117 and a wireless communication device 121 conductively bonded toantenna 119.

However, RFID tag 111 differs from RFID tag 11 in that RF inlay 113 ispositioned within a two-piece plastic casing 115 whereas RF inlay 13 ispositioned within a unitary plastic extrudate 15.

Specifically, casing 115 includes an elongated bottom member 123 whichis manufactured out of plastic. Bottom member 123 is preferably shapedto have a corrugated type of construction, bottom member 123 beingU-shaped in lateral cross-section along its length so as to define alongitudinal rectangular cavity 125 therewithin. It should be noted thatbottom member 123 is uniform in cross-section with cavity 125 extendingits entire length. Preferably, bottom member 123 is formed in one stepthrough an extrusion process.

Cavity 125 is sized and shaped to receive RF inlay 113. After RF inlay113 has been placed within cavity 125 of bottom member 123, an elongatedtop member 127 is applied to bottom member 123 so as to substantiallyenclose longitudinal cavity 125 along its length with antenna 119 andwireless communication device 121 positioned therewithin. (It should benoted that a small space or air gap exists between inlay 113 and topmember 127.) Top member 127 is preferably formed through an extrusionprocess.

In order to fully enclose antenna 119 and wireless communication device121 within longitudinal cavity 125, the free ends of two-piece casing115 are preferably crimped. However, it should be noted that casing 115is not represented in the drawings as being crimped at its ends forsimplicity purposes only.

Like RFID tag 11, RFID tag 111 may include a metallic reflector 151which is laminated onto the underside of bottom member 123 and/or amounting adhesive 155 which is laminated onto the underside of metallicreflector 151. It should be noted that the application of metallicreflector 151 to the underside of bottom member 123 is optional and isonly preferred when the item to which RFID tag 111 is to be secured ismetallic in nature. Furthermore, it should be noted that, where it isnot necessary or desirable to adhesively mount tag 111 onto an article,adhesive 155 is not needed and the application of mounting adhesive 155onto the underside of metallic reflector 151 may be eliminated from theassembly process.

Referring now to FIG. 7, there is shown a simplified schematicrepresentation of an automated method for continuously manufacturing asupply of RFID tags 111. For simplicity purposes only, the continuoussupply of RFID tags 111 is shown without metallic reflector 151 andadhesive 155. However, it is to be understood that metallic reflector151 and adhesive 155 could be introduced into the automated process inthe same manner in which reflector 51 and adhesive 55 were introducedinto the above-described method of manufacturing RFID tags 11.

In the process for manufacturing RFID tags 111, an extruder 157generates a continuous extrudate strip 159 which has a uniform, U-shapedlateral cross-section along its length. As a result, continuous strip159 defines a continuous longitudinal cavity 161. It should be notedthat continuous strip 159 can be cut (in a later step to be describedfurther below) to generate a plurality of bottom members 123. Aplurality of interconnected inlays 113 produced in the form of an RFinlay supply roll 163 are introduced from a reel 165 into elongatedcavity 161.

With the plurality of interconnected inlays 113 deposited in-line withincavity 161, a secondary extruder 167 generates a continuous plastic web169 which is applied in-line to the top of strip 159. It should be notedthat web 169 can be cut (in a later step to be described further below)to generate a plurality of top members 127. Web 169 is brought togetherwith continuous strip 159 to substantially enclose interconnected RFinlays 113 within cavity 161.

It should be noted that web 169 may be affixed to strip 159 using anyone of a variety of different methods. As an example, web 169 may be hotwhen applied to strip 159 to promote the adhesion therebetween. Asanother example, web 169 may be cool when initially applied to strip 159but then subsequently heated after said application step to promote theadhesion therebetween. As another example, web 169 may be affixed tostrip 159 using a conventional adhesive.

In the final steps of the assembly process, the continuous strip 159 andweb 169 (along with any reflectors 151 and adhesives 155 affixedthereto) are crimped between adjacent antennae 119 to fully enclose eachantenna 119 and wireless communication device 121 within cavity 161.After the crimping process, the continuous strip 159 and web 169 (alongwith any reflectors 151 and adhesives 155 affixed thereto) are cutbetween adjacent antennae 119 to form the individual RFID tags 111.Sensors (not shown) located along the continuous assembly line may beused to locate antennae 119 within cavity 161 during the crimping andcutting processes.

It should be noted that, although the process for fabricating tag 111 asdescribed above includes, among other things, affixing web 169 to strip159 and then cutting the resulting assembly into individual tags, onecould first cut strip 159 and web 169 into respective pluralities ofindividual bottom members 123 and individual top members 127 and thenaffix the individual top members 127 to the individual bottom members123.

Referring now to FIGS. 8 and 9, there are shown perspective and sectionviews, respectively, of a third embodiment of a radio frequencyidentification (RFID) tag constructed according to the teachings of thepresent invention and identified generally by reference numeral 171.

Tag 171 is similar in most respects to tag 111, the principal differencebetween the two tags being that tag 171 does not include a top member127. Instead, tag 171 includes a plug 177, plug 177 being positioneddirectly on top of inlay 113 and occupying some or all of the remainingspace of cavity 125 of bottom member 123. Accordingly, as can readily beappreciated, tag 171 does not possess an air gap over inlay 113 of thetype described above in connection with tag 111.

Plug 177 may be formed, for example, by extruding molten plastic overinlay 113 until cavity 125 is partially or completely filled and thenallowing the molten plastic to cool and harden in place. Alternatively,plug 177 may be formed by pouring into cavity 125 a suitable non-moltenpolymer and causing or allowing such a polymer to solidify in place.Examples of such polymers include (i) emulsion-based or solvent-bornepolymers and (ii) curable polymers including, but not limited to,two-part polymers (such as two-part epoxies), photo-curable polymers,and air-curable polymers.

It should be noted that plug 177 may be formed prior to the cutting ofstrip 159 into individual bottom members 123 or after the cutting ofstrip 159 into individual bottom members 123.

Referring now to FIG. 10, there is shown a perspective view of a fourthembodiment of a radio frequency identification (RFID) tag constructedaccording to the teachings of the present invention, said RFID tag beingidentified generally by reference numeral 181.

Tag 181 is similar in most respects to tag 111, the principal differencebetween the two tags being that tag 181 does not include a trough-shapedbottom member 123, but rather, includes a rectangular prismatic bottommember 183, inlay 113 being sandwiched between bottom member 183 and topmember 127.

Referring now to FIG. 11, there is shown a simplified schematicrepresentation, partly in section, of an automated method forcontinuously manufacturing a supply of RFID tags 181. For simplicitypurposes only, the continuous supply of RFID tags 181 is shown withoutmetallic reflector 151 and adhesive 155. However, it is to be understoodthat metallic reflector 151 and adhesive 155 could be introduced intothe automated process in the same manner in which reflector 51 andadhesive 55 were introduced into the above-described method ofmanufacturing RFID tags 11.

In the process for manufacturing RFID tags 181, an extruder 185generates a continuous extrudate 186 in the form of a rectangular block.A plurality of interconnected inlays 113 manufactured in the form of anRF inlay supply roll 163 are unwound from a reel 165 and laid on top ofextrudate block 186.

With the plurality of interconnected inlays 113 deposited on top ofextrudate block 186, a secondary extruder 187 generates a continuousplastic web 189 which is applied in-line over the interconnected inlays113 and any exposed areas on top of extrudate block 186. In this manner,web 189 and extrudate block 186 cooperatively surround interconnected RFinlays 113.

It should be noted that web 189 may be affixed to extrudate block 186using any one of a variety of different methods. As an example, web 189may be hot when applied to extrudate block 186 to promote the adhesiontherebetween. As another example, web 189 may be cool when initiallyapplied to extrudate block 186 but then subsequently heated after saidapplication step to promote the adhesion therebetween. As anotherexample, web 189 may be affixed to extrudate block 186 using aconventional adhesive.

In the final steps of the assembly process, extrudate block 186 and web189 (along with any reflectors 151 and adhesives 155 affixed thereto)are crimped between adjacent antennae 119 to fully enclose each antenna119 and wireless communication device 121 between extrudate block 186and web 189. After the crimping process, extrudate block 186 and web 189(along with any reflectors 151 and adhesives 155 affixed thereto) arecut between adjacent antennae 119 to form the individual RFID tags 181.Sensors (not shown) located along the continuous assembly line may beused to locate antennae 119 during the crimping and cutting processes.

It should be noted that, although the process for fabricating tag 111 asdescribed above includes, among other things, affixing web 189 toextrudate block 186 and then cutting the resulting assembly intoindividual tags, one could first cut block 186 and web 189 intorespective pluralities of individual bottom members 183 and individualtop members 127 and then affix the individual top members 127 to theindividual bottom members 183.

Referring now to FIGS. 12 and 13, there are shown perspective andsection views, respectively, of a fourth embodiment of a radio frequencyidentification (RFID) tag constructed according to the teachings of thepresent invention and identified generally by reference numeral 211.

RFID tag 211 is similar in construction to RFID tag 111 in that RFID tag211 comprises a radio frequency (RF) inlay 213 which is enclosed withina two-piece plastic casing 215.

RF inlay 213 is similar in construction to RF inlay 113 in that RF inlay213 comprises a carrier sheet 217 preferably manufactured as a web ofheat-stable polymeric film, an antenna 219 printed directly onto the topsurface of carrier sheet 217 and a wireless communication device 221conductively bonded to antenna 219.

Two-piece plastic casing 215 is similar in construction to casing 115 inthat two-piece plastic casing 215 comprises a bottom member 223 shapedto define a cavity 225 and a top member 227 affixed to bottom member 223over cavity 225. It should be noted that cavity 225 of bottom member 223is sized and shaped to receive an individual RF inlay 213.

Two-piece plastic casing 215 differs from casing 115 in that bottommember 223 has a different shape that bottom member 113. Specifically,bottom member 223 is shaped such that cavity 225 extends only a portionof its length. More specifically, cavity 225 does not extend to eitherof the free ends of bottom member 223. Rather, cavity 225 only extendswithin the middle section of the length of bottom member 223. Due to theparticular construction of bottom member 223, the securement of topmember 227 onto bottom member 223 serves to completely enclose cavity225 (with an RF inlay 213 disposed therein).

RFID tag 211 is similar to RFID tag 111 in that RFID tag 211 includes ametallic reflector 251 which is laminated onto the underside of bottommember 223 and a mounting adhesive 255 which is laminated onto theunderside of metallic reflector 251. It should be noted that theapplication of metallic reflector 251 to the underside of bottom member223 is optional and is only preferred when the item to which RFID tag211 is to be secured is metallic in nature. Furthermore, it should benoted that, where it is not necessary of desirable to adhesively mounttag 211 onto an article, adhesive 255 is not needed and the laminationof mounting adhesive 255 onto the underside of metallic reflector 251may be eliminated from the assembly process.

An automated method for continuously manufacturing a supply of RFID tags211 may be accomplished in the following manner. An extruder generates acontinuous extrudate strip which is substantially flat. In a subsequentthermoforming process, the continuous strip is provided with a pluralityof equidistantly spaced, downwardly protruding projections, eachprojection being shaped to define a corresponding cavity 225. In thisrespect, the thermoforming process serves to provide the continuousstrip with an egg-crate-type of construction.

After said thermoforming process, an individual RF inlay 213 isdeposited in-line, by hand or machine, into an associated cavity 225 inthe continuous strip. It should be noted that the supply of individualRF inlays 213 can be mass produced by printing a plurality of antennae219 on a continuous web at spaced intervals, soldering a wirelesscommunication device 221 onto each antenna 219 and cutting thecontinuous web between successive antennae 219 to define the individualRF inlays 213.

After said deposition step, a secondary extruder generates a continuousplastic web which is applied in-line to the top of the continuous strip.It should be noted that, by applying the plastic web onto the continuousstrip, each cavity 225 becomes completely enclosed by casing 215. Inthis respect, each individual RF inlay 213 becomes encased on all sideswithin plastic casing 215.

It should be noted that the plastic web may be affixed to continuousstrip using any one of variety of different methods. As an example, theplastic web may be hot when applied to the continuous strip to promotethe adhesion therebetween. As another example, the plastic web may becool when initially applied to the continuous strip but thensubsequently heated after said application step to promote the adhesiontherebetween. As another example, the plastic web may be affixed to thecontinuous strip using a conventional adhesive.

After said application step, the continuous strip and the plastic webare crimped (as deemed necessary) and cut between successive protrusionsformed in the continuous strip to form the supply of individual RFIDtags 211.

It should be noted that metallic reflector 251 and/or adhesive 255, ifrequired, could be laminated (directly or indirectly) onto bottom member223 prior to said cutting step (in a similar manner in which reflector51 and adhesive 55 are continuously in-line laminated onto extrudate 15)or after said cutting step (e.g., through manual application).

It should also be noted that, although the process for fabricating tag211 as described above includes, among other things, affixing the web oftop members 227 to the strip of bottom members 223 and then cutting theresulting assembly into individual tags, one could first cut the web oftop members 227 and the strip of bottom members 223 into respectivepluralities of individual top members 227 and individual bottom members223 and then affix the individual top members 227 to the individualbottom members 223.

Referring now to FIG. 14, there is shown a section view of a fifthembodiment of a radio frequency identification (RFID) tag constructedaccording to the teachings of the present invention and identifiedgenerally by reference numeral 311.

Tag 311 is similar in many respects to tag 211, the principaldifferences between the two tags being that tag 311 has a bottom member312, instead of bottom member 223, and that tag 311 includes a plug 313,instead of top member 227. Plug 313 is positioned directly on top ofinlay 213 and occupies some or all of the remaining space within bottommember 312. Plug 313 is similar in composition to plug 177 of tag 171and may be formed in the same manner as plug 177.

It should be noted that individual members 312 may be formed by cuttinga strip of interconnected bottom members 312 and that plug 313 may beformed prior to the cutting of said strip of interconnected bottommembers 312 into individual bottom members 312 or after the cutting ofsaid strip of interconnected bottom members 312 into individual bottommembers 312.

The embodiments shown in the present invention are intended to be merelyexemplary and those skilled in the art shall be able to make numerousvariations and modifications to it without departing from the spirit ofthe present invention. All such variations and modifications areintended to be within the scope of the present invention as defined inthe appended claims.

1. A tag comprising: (a) an inlay, said inlay comprising (i) an antenna,and (ii) a wireless communication device coupled to said antenna; and(b) a plastic extrudate, said plastic extrudate encapsulating saidantenna and said wireless communication device.
 2. The tag as claimed inclaim 1 wherein said plastic extrudate is a one-piece member, saidantenna and said wireless communication device being embedded withinsaid plastic extrudate.
 3. The tag as claimed in claim 1 wherein saidwireless communication device is a radio frequency (RF) communicationdevice.
 4. The tag as claimed in claim 1 wherein said inlay furthercomprises a carrier sheet, said antenna being printed onto said carriersheet.
 5. The tag as claimed in claim 1 further comprising a metallicreflector coupled to said plastic extrudate.
 6. The tag as claimed inclaim 1 further comprising a mounting adhesive coupled to said plasticextrudate.
 7. The tag as claimed in claim 1 wherein said wirelesscommunication device is in the form of an integrated circuit (IC) chipwhich is conductively bonded to said antenna.
 8. The tag as claimed inclaim 1 wherein said antenna is a bilaterally symmetrical dipoleantenna.
 9. The tag as claimed in claim 1 wherein said inlay furthercomprises a carrier sheet, said antenna being disposed on said carriersheet, and wherein said plastic extrudate comprises a top plasticextrudate member and a bottom plastic extrudate member, the bottomplastic extrudate member being shaped to include a cavity adapted toreceive said antenna and said wireless communication device, whereinsaid top plastic extrudate member and said bottom plastic extrudatemember cooperatively encapsulate said antenna and said wirelesscommunication device.
 10. A method of continuously manufacturing aplurality of tags, each tag comprising a plastic extrudate and an inlaysurrounded by said plastic extrudate, said method comprising the stepsof: (a) providing a continuous supply of inlays, said continuous supplyof inlays comprising a continuous carrier web, a plurality of antennaepositioned on said continuous carrier web at spaced intervals and awireless communication device coupled to each of said antennae, (b)feeding said continuous supply of inlays into a cross-head extruder soas to yield a continuous block which includes said continuous supply ofinlays surrounded by a plastic extrudate, and (c) cutting saidcontinuous block between successive antennae so as to yield individualtags.
 11. The method of claim 10 further comprising the step of couplinga mounting adhesive to the underside of said continuous block.
 12. A tagcomprising: (a) a plastic casing comprising (i) a bottom member shapedto define a longitudinal cavity, and (ii) a top member applied to saidbottom member to at least partially enclose the longitudinal cavity, and(b) an inlay disposed within the longitudinal cavity, said inlaycomprising, (i) a carrier sheet, (ii) an antenna disposed on saidcarrier sheet, and (iii) a wireless communication device coupled to saidantenna.
 13. The tag as claimed in claim 12 wherein said wirelesscommunication device is a radio frequency (RF) communication device. 14.The tag as claimed in claim 12 wherein said antenna is printed onto saidcarrier sheet.
 15. The tag as claimed in claim 12 further comprising amounting adhesive coupled to said plastic casing.
 16. The tag as claimedin claim 12 wherein said wireless communication device is in the form ofan integrated circuit (IC) chip which is conductively bonded to saidantenna.
 17. The tag as claimed in claim 12 wherein the longitudinalcavity extends the entire length of said bottom member.
 18. The tag asclaimed in claim 17 wherein the longitudinal cavity is generallyU-shaped in longitudinal cross-section.
 19. The tag as claimed in claim12 wherein the top member is a flat sheet affixed to said bottom member.20. The tag as claimed in claim 12 wherein the longitudinal cavityextends only a portion of the length of said bottom member.
 21. The tagas claimed in claim 20 wherein the longitudinal cavity is spacedinwardly from both ends of said bottom member.
 22. The tag as claimed inclaim 12 wherein the top member is a plug molded to said bottom member.23-37. (canceled)